I let one of my broody banties lay on and hatch her own eggs last fall. It was my first experience with hatching and I decided it would be best to let nature take it's course rather than mess it up with my own lack of knowledge and inexperience. She did great. She sat for a month on those eggs, only coming off occassionaly to eat and drink. I candled them about 3 weeks into it, couldn't tell anything, almost threw them out, but decided to give her a couple more weeks. I was so thrilled when they actually hatched out. She was sitting on five eggs, and all five hatched. Here are the pros and cons I realized with doing this...
Pros: 1) the hen did all the work herself 2) it was awsome getting to watch her carre for them and protect them
Cons: 1)one of the chicks died from falling out of the nest box, which sits about two foot off the ground. It either fell out and the fall killed it, or one of the other hens killed it, or it simply died from being too cold for too long. 2) The mom would not leave her chicks to go eat, therefore, she was pratically starving herself and the chicks. 3) The "head" hen tried her best to kill the chicks, pecking at the mother's head until her rose comb was completely pecked off. The mother would hide her chicks under her while she was pecked on the head persifully by the other hen. I was horrified when I realized this! 3) It was impossible to keep the mother and babies with this other hen, so I was forced to separate them by putting the mother and chicks in a brooder in the garage until we put up a dividing chicken wire wall in the coop to protect them from the other hen. This was not an easy process. 4) because the chicks were raised by their mother, they are more wild than the flocks I have hand raised. They are way more leary of me and I am not able to pick them up or anything.
I guess it just depends on your setup, but the hardest part for me was the way the "head" hen handled the situation of having new chicks in the flock. They are grown and laying eggs of their own now, and I hope to be able to free range them some together this summer. I don't know how the "head" hen will do with them, I am just crossing my fingers and hope that no one gets hurt. Good luck with your eggs! Keep us posted on how they do.